Huge crowds lined the streets of the holy city of Mashhad for the burial of Iran’s late supreme leader Ayatollah Ali Khamenei.

Khamenei was buried at the shrine of Imam Reza, the holiest Shiite Muslim site in Iran, marking the end of six days of public mourning ceremonies in five cities in Iran and neighboring Iraq.

The burial, reported by state news agency IRNA, came after an exchange of attacks between Iran and the United States that threatens to derail a preliminary agreement to end the war in which he died.

Earlier, Iran’s Revolutionary Guard accused the United States of bombing two bridges on the railway line from the capital, Tehran, to Mashhad overnight “in an effort to upstage” the funeral.

Khamenei and several members of his family were killed in an Israeli attack on his residence in Tehran on February 28, the first day of Iran’s war with the United States and Israel.

He was succeeded as supreme leader by his son Mojtaba, who has not been seen in public since he was reportedly seriously injured in the same attack.

The 56-year-old did not take part in the funeral ceremonies in Tehran and Qom, and there was no indication he had attended the burial.

On Thursday morning, a plane carrying the coffins of Ali Khamenei, his granddaughter, his son-in-law, his daughter and Mojtaba’s wife landed in Mashhad after flying from Iraq, where large crowds took part in processions to two Shiite shrines in the cities of Najaf and Karbala.

In the afternoon, Iranian television footage showed thousands of mourners dressed in black walking along a main boulevard in the center of Mashhad. Many waved Iranian flags and red banners symbolizing revenge.

Some people also held photographs of the late supreme leader and banners calling for the death of US President Donald Trump, who, along with Israeli Prime Minister Benjamin Netanyahu, ordered the joint attack on Iran four months ago that sparked the war.

Hanging over the boulevard were banners with official slogans including “We must rise.”

“The loss of the leader is heavier than the loss of our parents,” Hoda, a 35-year-old housewife, told AFP. “Only the death of Trump and Netanyahu will ease our pain.”

Later, a truck slowly carried Khamenei’s coffin through the crowd toward Imam Reza’s shrine, finally arriving at the complex as night fell.

Imam Reza was the eighth Shiite imam and the only one of the 12 believed to have been buried in Iran. His mausoleum, which dates back to the 9th century and has an imposing golden dome and minarets, is visited by millions of pilgrims each year.